JP2001166624A - Oil removing sheet, oil removing material and oil removing device for oil attaching substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil removing sheet, an oil removing material and an oil removing device by which the oil of an oil attaching substance can be uniformly wiped out and removed. SOLUTION: In the cross section of a fiber sheet including binding resin binding mutual heat resistance fibers which do not melt even when they are brought into contact with the oil attaching substance, the binding resin existing in an area to 20 μm in the thickness direction of the fiber sheet from one surface A is bound in a state where the length thereof in a direction orthogonally crossing the thickness direction of the fiber sheet is mainly longer than the thickness-direction length of the fiber sheet. Besides, the average area ratio occupied by the constituting material of the fiber sheet other than the binding resin existing in the area A with respect to the whole of the constituting material of the fiber sheet is equal to or under 25% and the average area ratio of the occupied by the constituting material of the fiber sheet other than the binding resin existing in the area to the 20 μm in the thickness direction of the fiber sheet from the other surface B with respect to the whole of the constituting material of the fiber sheet existing in the area B is over 25%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an oil removing sheet for oil deposits, an oil removing material for oil deposits, and an oil removing device for oil deposits.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic apparatus such as a copying machine, a laser beam printer, and a facsimile, a copy sheet (eg, paper, film, etc.) carrying an unfixed toner image between a fixing roll and a pressure roll. And the toner is fixed on the surface of the copy sheet by the action of heat and pressure. Therefore, the toner is transferred to the surface of the fixing roll and / or the pressure roll, and the transferred toner is transferred again to the rear end portion of the copy sheet or to the next copy sheet passing therethrough, thereby soiling the copy sheet (so-called offset). There was a problem. Therefore, oil is applied to the surface of the fixing roll to improve the releasability of the toner from the surface of the fixing roll, and then the toner is wiped off with a cleaning sheet.

The fixing of the toner will be described with reference to FIG. 1 which is a schematic cross-sectional view of a fixing section. First, an unfixed toner image 3a is placed between a fixing roll 1 and a pressure roll 2.
Is supplied. When the copy sheet 3 passes between the fixing roll 1 and the pressure roll 2, the unfixed toner 3a is fixed to the copy sheet 3 by the action of heat and pressure, and then the copy sheet 3 is discharged. . On the other hand, the oil 4a is applied to the fixing roll 1 from the oil applying device 4 at a stage before the fixing roll 1 comes into contact with the copy sheet 3 in order to enhance the releasability of the toner. Next, the fixing roll 1 fixes the unfixed toner 3 a to the copy sheet 3, and then the remaining toner that has not been fixed is wiped off by the cleaning sheet 5.

[0004] In this manner, the unfixed toner 3
Since a is fixed, the oil applied to the fixing roll is transferred to the copy sheet 3 in addition to the toner. for that reason,
When the copy sheet 3 is made of paper and has a portion where the toner is not fixed, the oil is absorbed by the portion where the toner is not fixed, so that no major problem occurs. However, when the toner is fixed on the entire surface of the copy sheet (for example, when copying a photo with a color copier) or when the copy sheet is a film,
In the former case, the toner does not absorb the oil, and in the latter case, the copy sheet does not absorb the oil, so that the oil remains on the fixed toner and the quality of the copied image deteriorates. In particular, the application of oil by the oil application device 4 is performed after the surface of the fixing roll is wiped with the cleaning sheet 5, but the cleaning sheet 5 conventionally used has a rough surface or poor fiber dispersibility. Alternatively, since the fibers tend to fluff easily, the oil is unevenly wiped by the cleaning sheet 5 at the same time as the toner is wiped, and the thickness of the oil remaining on the fixing roll surface is uneven (see FIG. 2A). ). Therefore, the oil application device 4
Even if the oil is uniformly applied by the method, unevenness of the oil thickness on the surface of the fixing roll is promoted (see FIG. 2).
As a result, the oil was unevenly transferred onto the toner fixed on the copy sheet, and the image quality was significantly reduced.

[0005] For this reason, an attempt was made to uniformly wipe off the oil by increasing the pressing force of the cleaning sheet 5 against the fixing roll 1, but the fixing sheet was easily pressed because the cleaning sheet 5 was pressed strongly, There are problems such as a shortening of the life of the fixing roll 1 and an increase in friction between the cleaning sheet 5 and the fixing roll 1 causing mechanical vibration. Attempts have also been made to reduce the amount of oil applied from the oil application device 4 to the fixing roll 1, but it is said that reducing the amount of oil deteriorates the releasability of the toner and tends to cause offset. There was a problem. Further, instead of bringing the cleaning sheet 5 into direct contact with the fixing roll 1, a transfer roll capable of transferring the residual toner on the surface of the fixing roll is provided. Attempts have also been made to remove oil and oil, but at present it has not been possible to completely eliminate the oil streaks on the copy sheet.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and can uniformly wipe off and remove oil on oil deposits such as the fixing roll. An object of the present invention is to provide an oil removing sheet, an oil removing material for oil deposits, and an oil removing device for oil deposits.

[0007]

The oil-removing sheet for oily deposits (hereinafter referred to as "oil-removal sheet") of the present invention is made of heat-resistant fiber which does not melt even when it comes into contact with the oily deposit from which oil is to be removed. And a fiber sheet containing a heat-resistant fiber-bonded resin, and a cross section of the fiber sheet extending from one surface (A) to 20 μm in the thickness direction of the fiber sheet (region A). Is bonded in a state where the length in the direction orthogonal to the thickness direction of the fiber sheet is longer than the length in the thickness direction of the fiber sheet, and The average area ratio of the fiber sheet components other than the binding resin to the entire fiber sheet components present in the region A is 25% or less, and the cross section of the fiber sheet The fibers present in the region B occupied by the fiber sheet constituent materials other than the binder resin existing in the region (region B) from the other surface (B) up to 20 μm in the thickness direction of the fiber sheet. The average area ratio with respect to the entire sheet constituting material exceeds 25%. As described above, the bonding resin existing in the region A is bonded in a flat state, and the fiber sheet existing in the region A occupied by the fiber sheet constituent materials other than the bonding resin existing in the region A. Since the average area ratio to the entire constituent material is 25% or less, that is, the binder resin occupies 75% or more, the fiber sheet surface (A) included in the region A is very smooth. Therefore, if the fiber sheet surface (A) included in the region A is brought into contact with the oil deposit, the oil on the oil deposit surface can be uniformly wiped and removed.
Also, the average area ratio of the fiber sheet components other than the binder resin present in the region B to the entire fiber sheet components present in the region B exceeds 25%, that is, 75% of the binder resin is present. And the area B has a coarser structure than the area A, so that the area B can retain a large amount of oil removed. The average fiber diameter of the fibers present in the region A is 11
When the particle size is not more than μm, the fiber sheet surface (A) contained in the region A is even smoother.
The oil on the surface of the oil deposits can be more evenly wiped off and removed.

[0008] Another oil removing sheet of the present invention is a fiber sheet comprising heat-resistant fibers that do not melt even when they come into contact with oil deposits from which oil is to be removed, and a binding resin that bonds the heat-resistant fibers to each other. And the average surface roughness (Ra) on one surface (A) of the fiber sheet is 3 μm or less, and the average surface roughness (Rb) on the other surface (B) of the fiber sheet exceeds 3 μm. Things. As described above, since the fiber sheet surface (A) having an average surface roughness (Ra) of 3 μm or less is very smooth, if the fiber sheet surface (A) is brought into contact with the oil deposit, the surface of the oil deposit is reduced. Oil can be evenly wiped off and removed. Further, since the fiber sheet surface (B) having an average surface roughness (Rb) of more than 3 μm has a rougher structure than the fiber sheet surface (A), it was removed near the fiber sheet surface (B). A large amount of oil can be retained.

[0009] The oil removing material for oil deposits of the present invention (hereinafter referred to as
The “oil removing material” is one in which one end of the above-described oil removing sheet is wound around a shaft, and the other end of the oil removing sheet is fixed to another shaft. This oil removal material can always contact the new side of the oil removal sheet with the oil deposit surface,
The oil on the surface of the oil deposit can be uniformly wiped and removed, and the removed oil can be retained in a large amount.

[0010] The oil removing device for oil deposits of the present invention (hereinafter referred to as "oil removing device") unwinds the oil removing sheet from the above-described oil removing material and applies the unwound oil removing sheet to the oil removing device by pressing means. After pressing on the kimono, it has a mechanism for winding up the pressed oil removal sheet. Since this oil removal device can always bring the new side of the oil removal sheet into contact with the surface of the oil deposit, the oil on the surface of the oil deposit is evenly wiped off,
At the same time, the oil removed can be retained in a large amount.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The fiber sheet constituting the oil removing sheet of the present invention can be, for example, a woven fabric, a knitted fabric, a nonwoven fabric, or a composite thereof. Among these, it is preferable to use a nonwoven fabric having excellent surface smoothness because the fibers can be arranged at random.

[0012] The fiber sheet of the present invention contains heat-resistant fibers that do not melt even when they come into contact with oil deposits from which oil is to be removed, and a binding resin that bonds the heat-resistant fibers to each other.
These heat-resistant fibers are included so that they do not break even when the oil removal sheet comes into contact with the oil deposits, and do not melt even when they come into contact with the oil deposits. For example,
In the case where the oil deposit from which oil is to be removed is a fixing roll of an electrophotographic apparatus, the surface temperature of the fixing roll may be 170.
Since it is about 230 ° C., a fiber having a melting point of 240 ° C. or more or a carbonization temperature of 280 ° C. or more can be used as a heat-resistant fiber. Further, when the oil deposit to be removed from the oil is a pressure roll of an electrophotographic apparatus, since the surface temperature of the pressure roll is about 100 to 180 ° C., the melting point is not less than 190 ° C. Temperature is 230 ° C
The above fibers can be used as heat-resistant fibers. Further, when the oil deposit from which the oil is to be removed is a transfer roll of an electrophotographic apparatus, the surface temperature of the transfer roll may be 1
Since the temperature is about 40 to 200 ° C., a fiber having a melting point of 210 ° C. or more or a carbonization temperature of 250 ° C. or more can be used as a heat-resistant fiber. The “melting point” in the present invention refers to a temperature at which a maximum value of a melting endothermic curve obtained by raising the temperature from room temperature at a temperature rise rate of 10 ° C./min using a differential calorimeter is given.
The term “carbonization temperature” refers to a temperature obtained by thermogravimetry defined in JIS K 7120. More specifically, as one group of heat-resistant fibers (hereinafter sometimes referred to as “first heat-resistant fibers”), meta-type or para-type aromatic polyamide fibers having a melting point or carbonization temperature exceeding 300 ° C. , Polyamideimide fibers, polytetrafluoroethylene fibers, aromatic polyetheramide fibers, polybenzimidazole fibers, aromatic polyester fibers, and the like. These first heat resistant fibers can be used alone or in appropriate combination of two or more kinds. Among these, aromatic polyamide fibers are less likely to shrink even at high temperatures, and are less likely to cause wrinkles in the fiber sheet. Such a first heat resistant fiber is contained in the fiber sheet in an amount of 10 mass% so that the oil removal sheet does not break even when it comes into contact with the oil deposit.
More preferably, it is contained, more preferably, 20 mass% or more. In addition, it is preferable to contain 60 mass% or less in a fiber sheet from the relationship with the binding resin described later. As a second group of heat-resistant fibers (hereinafter, sometimes referred to as "second heat-resistant fibers"), there may be mentioned fibers which have a softening temperature of 300 ° C or lower and which are not melted by the heat of oil deposits but are softened. it can. Such a second heat resistant fiber is deformed along the surface of the oil deposit when it comes into contact with the oil deposit, and the smoothness of the oil removal sheet can be further improved.
In addition, the deformation of the second heat-resistant fiber increases the contact area between the oil removal sheet and the oil deposits, and can reduce the pressing force of the oil removal sheet against the oil deposits, thereby damaging the oil deposits. It also has the effect of making it difficult to perform. This “softening temperature” is defined in JIS K 712
Heat flux differential scanning calorimetry (DSC,
The temperature gives a starting point of a melting endothermic curve in a DSC curve obtained by a temperature rise temperature of 10 ° C./min. This second
Examples of the heat-resistant fibers include polyamide fibers such as 6 nylon fibers and 66 nylon fibers, polyester fibers such as drawn polyethylene terephthalate fibers and drawn polybutylene terephthalate fibers, acrylic fibers, vinylon fibers, and drawn polyphenylene sulfide fibers. Can be mentioned. This second heat-resistant fiber can be used alone or in combination of two or more.
Moreover, you may use together a 1st heat resistant fiber and a 2nd heat resistant fiber. Among these second heat-resistant fibers, drawn polyethylene terephthalate fibers are preferred. In particular, when the oil deposit is a substance having a high temperature such as a fixing roll, a pressure roll or a transfer roll of an electrophotographic apparatus, the melting point is 255.
A drawn polyethylene terephthalate fiber which is as high as about ° C and does not soften or melt at the ambient temperature of the place where the oil deposits are placed can be suitably used. Such a second heat-resistant fiber is preferably contained in the fiber sheet in an amount of 0 to 30 mass%, more preferably 2 to 20 mass%. If the average fiber diameter of the first heat-resistant fiber and the second heat-resistant fiber is too large, it becomes difficult to smooth the surface of the oil removal sheet. The average fiber diameter of each is preferably 14 μm or less, more preferably 12.5 μm or less. Although the lower limit is not particularly limited, about 5 μm is appropriate. Further, the average fiber diameter of the first heat-resistant fiber and the second heat-resistant fiber as a whole is also preferably 14 μm or less,
It is more preferably 12.5 μm or less, and 11.5 μm or less.
m is more preferable. Although the lower limit is not particularly limited, about 5 μm is appropriate. The `` fiber diameter '' in the present invention refers to the diameter of the fiber when the cross-sectional shape of the fiber is circular, and the diameter of a circle having the same area as the cross-sectional area when the cross-sectional shape of the fiber is non-circular. Consider as diameter. The “average fiber diameter” refers to the average value of the fiber diameters of 100 randomly selected fibers. The heat-resistant fiber (for example, the first heat-resistant fiber, which constitutes the oil removal sheet of the present invention,
The cross-sectional shape of the second heat-resistant fiber or the like does not need to be circular, and may be a non-circular shape such as a polygonal shape (for example, a triangle or a quadrangle) or an alphabetical shape (for example, a Y shape or an X shape). . In addition, heat-resistant fiber (for example, 1st
When the cross-sectional shape of the heat-resistant fiber, the second heat-resistant fiber, etc.) is flat, the oil removal sheet has more excellent smoothness.

[0013] The fiber sheet constituting the oil removal sheet of the present invention maintains the fiber sheet shape and the surface of the oil removal sheet at the same time as the heat resistant fibers are bonded to each other by the bonding resin. Excellent smoothness. The bonding resin is not particularly limited as long as it can bond the heat-resistant fibers. However, the bonding resin has a high temperature such as a fixing roll, a pressure roll or a transfer roll of an electrophotographic apparatus. In such a case, it is preferable to use a heat-resistant binding resin. Examples of such a heat-resistant binding resin include polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, nylon such as 6 nylon and 66 nylon. This binding resin is 1
The types or two or more types can be appropriately combined. Among these, polyethylene terephthalate can be suitably used because the bonding strength does not decrease even when exposed to high temperatures. This binding resin makes it easy to smooth the fiber sheet surface,
Preferably, the fiber sheet contains 50 mass% or more, more preferably 55 mass% or more, and most preferably 60 mass% or more. In addition, heat-resistant fibers (for example, first heat-resistant fiber and / or
Since it is preferable to mix the second heat-resistant fiber), the content of the binder resin in the fiber sheet is preferably 95% by mass or less, more preferably 90% by mass or less.
Most preferably, it is 0 mass% or less.

[0014] The oil removal sheet of the present invention is constituted by a fiber sheet made of the above-mentioned fibers, and the cross section of the fiber sheet extends from one surface (A) to 20 μm in the thickness direction of the fiber sheet. The bonding resin present in the region (region A) is bonded in a state where the length in the direction orthogonal to the thickness direction of the fiber sheet is longer than the length in the thickness direction of the fiber sheet. The average area ratio of the fiber sheet components other than the binder resin present in the region A to the entire fiber sheet components present in the region A is 25% or less, and in the cross section of the fiber sheet. , In the region B occupied by fiber sheet constituent materials other than the binder resin existing in a region (region B) up to 20 μm in the thickness direction of the fiber sheet from the other surface (B). The average area ratio to the entire fibrous sheet construction material has is in the state exceeding 25%. As described above, the binder resin present in the region A is bonded in a flat state, and the fiber sheet component present in the region A is occupied by the fiber sheet component other than the binder resin present in the region A. Since the average area ratio to the whole is 25% or less, that is, the binding resin occupies 75% or more, the fiber sheet surface (A) included in the region A is very smooth. Therefore, if the fiber sheet surface (A) included in the region A is brought into contact with the oil deposit, the oil on the oil deposit surface can be uniformly wiped and removed. Also, the average area ratio of the fiber sheet components other than the binder resin present in the region B to the entire fiber sheet components present in the region B exceeds 25%, that is, 75% of the binder resin is present. And area B is area A
Since it has a coarser structure, a large amount of oil removed by this region B can be retained. The cross section of such a fiber sheet can be easily confirmed from, for example, an electron micrograph. The one surface (A) and the other surface (B) are present in the respective regions from both surfaces of the fiber sheet up to 20 μm in the thickness direction of the fiber sheet, other than the binder resin. , The average area ratio with respect to the entire fiber sheet component existing in each region is derived, and as a result, the surface included in the region where the average area ratio is 25% or less is defined as the surface (A).
The surface included in the region where the average area ratio exceeds 25% is defined as surface (B). In addition, "surface" means when a flat plate of 1 g per 1 cm ² is laminated on a fiber sheet,
A virtual surface that coincides with the surface of the flat sheet on the fiber sheet side is regarded as the surface of the fiber sheet. The “thickness direction” of the fiber sheet refers to a direction orthogonal to the surface of the fiber sheet. The bonding resin present in the region A as described above is bonded in a state where the length in the direction orthogonal to the thickness direction of the fiber sheet is longer than the length in the thickness direction of the fiber sheet. That is, since the binding resin is bound in a flat state parallel to the fiber sheet surface, the surface (A) is very smooth. The “length of the binder resin in the thickness direction of the fiber sheet” refers to the longest length parallel to the thickness direction of the fiber sheet, and the “length in the direction perpendicular to the thickness direction of the fiber sheet of the binder resin”. The “length” refers to the longest length parallel to a direction perpendicular to the thickness direction of the fiber sheet (parallel to the surface of the fiber sheet). The fiber sheet of the present invention is present in the region A where the fiber sheet constituent material (for example, the first heat-resistant fiber and / or the second heat-resistant fiber) other than the binder resin is present in the region A. The average area ratio to the entire fiber sheet constituent material (for example, the first heat resistant fiber, the second heat resistant fiber, the binding resin, etc.) is 25.
%, That is, the binding resin in a flat state as described above has an average area ratio of 75% or more, so that the surface (A) of the fiber sheet is very smooth. The average area ratio refers to the average value of the area ratios calculated from the cross sections of the fiber sheets at 10 locations by the following formula. The lower the average area ratio is, the smoother the surface (A) of the fiber sheet is. The average area ratio is preferably 20% or less, more preferably 15% or less, even more preferably 10% or less. Area ratio (%) = (K / T) × 100 Here, “K” means an area occupied by fiber sheet constituent materials other than the binding resin present in each region in the cross section of the fiber sheet, and “T” is a fiber sheet. It means the area occupied by the entire fiber sheet component present in each region in the cross section. If the average fiber diameter of the fibers (for example, the first heat-resistant fiber and the second heat-resistant fiber) existing in the region A is 11 μm or less (more preferably, 10 μm or less and about 5 μm or more), the region A This is suitable because the smoothness of the surface A of the fiber sheet contained in the above is further improved. Incidentally, the average fiber diameter of the individual fibers present in the region A is also preferably 11 μm or less, more preferably 10 μm or less,
Most preferably, it is 9 μm or less. The lower limit is 5μ
It is suitably about m or more. Fiber present in region B occupied by a fiber sheet constituent material (eg, first heat-resistant fiber and / or second heat-resistant fiber) other than the binding resin present in region B of the fiber sheet of the present invention. The average area ratio to the entire sheet constituent material (for example, the first heat-resistant fiber, the second heat-resistant fiber, the binding resin, etc.) exceeds 25%, that is, the region B has a rougher structure than the region A as described above. Therefore, the oil removed by the region B including the surface (B) of the fiber sheet can be retained in a large amount. The average area ratio is a value derived in the same manner as in the case of the region A. The higher the average area ratio is, the coarser the structure is and the more excellent the oil retention is. Is preferably 30% or more, more preferably 40% or more, and 5% or more.
Most preferably, it is 0% or more. On the other hand, since a binding resin is required for maintaining appropriate strength, the content is preferably 80% or less, and more preferably 70% or less.
Fibers existing in the region B (for example, first heat-resistant fibers,
The average fiber diameter of the second heat-resistant fiber is preferably 15 μm or less so as to easily hold oil. Also,
Each of the fibers present in the region B (for example, the first heat-resistant fiber, the second heat-resistant fiber, etc.) has an average fiber diameter of 1
It is preferably 5 μm or less. Region A and region B
Is preferably 25% or more,
It is more preferably at least 5%, and even more preferably at least 40%.

[0015] Another oil removal sheet of the present invention is constituted by a fiber sheet comprising the above-mentioned fibers, and has an average surface roughness (Ra) on one surface (A) of the fiber sheet of 3 µm or less; And the other surface of the fiber sheet (B)
Has an average surface roughness (Rb) of more than 3 μm. As described above, since the fiber sheet surface (A) having an average surface roughness (Ra) of 3 μm or less is very smooth, if the fiber sheet surface (A) is brought into contact with oil deposits,
The oil on the surface of the oil deposit can be evenly wiped off and removed. Further, since the fiber sheet surface (B) having an average surface roughness (Rb) of more than 3 μm has a rougher structure than the fiber sheet surface (A), it was removed near the fiber sheet surface (B). A large amount of oil can be retained. The one surface (A) and the other surface (B) measure the average surface roughness on both surfaces of the fiber sheet, and as a result, the surface having an average surface roughness of 3 μm or less is defined as a surface (A). The surface having an average surface roughness exceeding 3 μm is defined as a surface (B). This average surface roughness (R
a, Rb) mean the average value of the surface roughness measured using a surface tester (KES-FB4, manufactured by Kato Tech) under the following conditions. (1) Standard pressure (P): 10 gf (2) Contact: A steel wire having a diameter of 0.5 mm is bent to have a contact length of 5 mm (3) Vertical displacement sensitivity: SENS 2 × 5: 10 V / 0 .
4 mm (4) Recorder sensitivity: X-axis-0.1 V / cm, Y-axis-0.
5V / cm (5) Contact moving speed: 1 mm / sec (6) Contact moving direction: Fiber sheet width direction (direction orthogonal to fiber sheet length direction) (7) Sample tension: 20 gf / cm ( 8) Sample size: 20 × 20 cm (9) Number of measurements: 10 Note that the average surface roughness (Ra) on the surface (A) is 2.
It is preferably 5 μm or less, more preferably 2 μm or less. The average surface roughness (Rb) on the surface (B) is preferably not less than 3.3 μm, and is preferably 3.5 μm.
More preferably, it is not less than μm. The upper limit of the average surface roughness (Rb) on the surface (B) is suitably about 5 μm.

[0016] The fiber sheet constituting the oil removal sheet of the present invention.
The surface density and thickness of the
The degree is 20-60 g / m^Two, The thickness is 40-120 μm
More preferably about 50 to 100 μm).
No. The apparent density of the oil removal sheet (fiber sheet)
Is 0.5 to 0.8 g / cm ^ThreeIt is preferred that Oy
The apparent density of the fiber removal sheet (fiber sheet) is 0.5g / c
m^ThreeIf it is less than 0.0, the smoothness tends to be poor.
8g / cm^ThreeExceeds the space for holding oil
This is because the oil retention capacity tends to decrease,
0.55 to 0.75 g / cm^ThreeIs more preferable
0.6 to 0.75 g / cm^ThreeIs even more preferable
No. The thickness of this oil removal sheet (fiber sheet)
Chromometer (JISB7502: measurement area φ6.
It refers to the value measured using 3).

[0017] The method for producing the fiber sheet constituting the oil-removing sheet of the present invention is not particularly limited. For example, an oil-removing sheet made of a nonwoven fabric can be produced as follows. First, a heat-resistant fiber (for example, a first heat-resistant fiber and / or a second heat-resistant fiber, etc.) and a material that forms a binder resin, for example, a binder fiber, a binder resin powder, a binder resin emulsion or latex, At least one kind selected from a binding resin film and a binding resin plate is prepared. Among these, it is preferable that the material from which the binding resin is formed is composed of binding fibers. Examples of the binding fiber include undrawn polyethylene terephthalate fiber, undrawn polybutylene terephthalate fiber, and undrawn polyphenylene sulfide fiber. When the oil deposit is a high-temperature substance such as a fixing roll, a pressure roll, or a transfer roll of an electrophotographic apparatus, the bonding force does not decrease even if the oil deposit comes into contact with the oil deposit, and the bonding temperature is relatively low. It is preferable to use undrawn polyethylene terephthalate fiber which has a wide bonding temperature range and is easy to bond. The average fiber diameter of the binding fiber is not particularly limited, but is preferably 27 μm or less, and more preferably 25 μm or less, so that the dispersibility of the binding fiber and the smoothness of the fiber sheet are excellent. ,
More preferably, it is 23 μm or less. The lower limit is not particularly limited, but is suitably about 10 μm. One method of manufacturing an oil-removing sheet is to form a fiber web containing heat-resistant fibers (for example, first heat-resistant fiber and / or second heat-resistant fiber) and then connect one surface of the fiber web to more bonding resin. Bonding with powder, bonding one side of fiber web with more bonding resin emulsion or latex, or bonding one side of fiber web with more bonding resin film or bonding resin plate, Sheets, ie, oil removal sheets, can be manufactured. Another method of manufacturing an oil removal sheet is
A fiber web A containing at least binding fibers and a fiber web B containing heat-resistant fibers (eg, first heat-resistant fibers and / or second heat-resistant fibers) and binding fibers are formed. And the fiber web B are laminated and then bonded by the bonding fiber, whereby the fiber sheet as described above, that is, the oil removal sheet can be manufactured. In this case, when the amount of the bonding fiber in the fiber web A is 75 mass% or more in the fiber web A, the surface (A) of the oil removal sheet of the present invention is easily formed, and the mass (80 mass%) is obtained.
It is preferably at least 85 mass%, more preferably at least 85 mass%. On the other hand, when the amount of the bonding fiber in the fiber web B is 30 to 60 mass% in the fiber web B, the surface (B) of the oil removal sheet of the present invention is easily formed, and preferably 35 to 55 mass%. , 40
More preferably, it is で 50 mass%. Examples of the method for forming the fiber web of the present invention include a dry method such as a card method and an air lay method, and a wet method. When the fibers are oriented in the length direction of the fiber web by the card method,
This is preferable because the strength in the length direction of the oil removing sheet can be increased and the oil removing sheet is not easily broken during use. In addition, even if it manufactures by any manufacturing method, so that it may be excellent in the smoothness of the fiber sheet surface (A),
It is preferred that the fiber web be entirely pressurized during or after bonding. By pressing the entire surface in this manner, the binding resin tends to be in a flat state. In addition, even if the oil deposit is at a high temperature, the oil removal sheet does not shrink due to contact with the oil deposit, and also has the effect of not impairing smoothness. For example, as in the latter, the fiber web A
When the fiber web B and the fiber web B are bonded to each other with the bonding fiber, for example, it is preferable to heat and press the laminated fiber web by a heat calender or to heat and press by a flat plate press to bond. When the unstretched polyethylene terephthalate fiber, which is a preferable binding fiber, is bonded by the former heat calender, the temperature is 170 to 250 ° C. and the linear pressure is 1 so that the fiber can be bonded smoothly and firmly and the thickness can be adjusted.
It is preferable to carry out at a temperature of 190 to 230 ° C. and a linear pressure of 300 to 700 N / cm. In the case of bonding with bonding fibers, if the fibers are entangled by a fluid flow such as a water flow and then bonded by bonding fibers, the bonding fibers are bonded in a state where there are many contact points between the fibers, and the tensile strength is increased. This is preferable because it is possible to improve the surface roughness, suppress fluffing, and improve the smoothness.

[0018] In the oil removing material of the present invention, one end of the oil removing sheet as described above is wound around a shaft (unwinding shaft), and the other end of the oil removing sheet is another shaft (winding shaft). It is fixed to. By unwinding the oil removal sheet sequentially from the unwinding shaft, this oil removal material can always contact a new oil removal sheet with oil deposits.
The oil can be removed so that the oil thickness is always uniform. As a method of fixing the oil removal sheet to the shaft, for example, (1) fixing with a double-sided tape,
(2) fixing with a fusion resin such as a hot melt resin,
(3) When the shaft is made of a thermoplastic resin, fixation by heat-sealing the shaft; (4) Fixation by installing a pin or the like on the shaft and inserting an oil removal sheet; (5) Groove on the shaft And fixing by inserting an oil removal sheet into the groove.
In the case of fixing by the above methods (1) to (3), it may be fixed to the entire surface of the shaft or may be partially fixed. In addition, on the unwinding shaft side, the oil removal sheet does not need to be fixed to the shaft, but may be simply wound around the shaft.

The oil removing device of the present invention unwinds the oil removing sheet from the above-described oil removing material, presses the unwound oil removing sheet against oil deposits by a pressing means, and winds up the pressed oil removing sheet. It has a mechanism. This oil removal device can always bring a new oil removal sheet into contact with oil deposits by unwinding the oil removal sheet sequentially from the unwinding shaft, thus removing the oil so that the oil thickness is always uniform. can do. As a means for pressing the oil removal sheet on the oil adhering material in the oil removal device of the present invention, for example, a rod-shaped body having a circular or polygonal cross section (for example, a square or a hexagon) can be used. Among them, a rod-shaped body having a circular cross section is preferable because the oil removal sheet can be pressed uniformly against the oil deposits and the oil can be easily removed uniformly. When the oil removing device of the present invention is used for removing oil from a fixing roll, a pressure roll, or a transfer roll of an electrophotographic apparatus or the like, the rod is preferably excellent in elasticity and heat resistance. It is preferably made of non-foamed silicone rubber. The pressing force on the oil deposits by the rod is set so that the working width (nip width) of the rod on the oil deposit surface is 2 to 5 mm so that the oil can be removed so that the oil thickness is uniform. It is preferable that the pressing force is a certain value. Further, the rod-shaped body is pressed so that the surface (A) of the oil removal sheet comes into contact with the oil deposit.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments.

[0021]

EXAMPLES Example 1 Unstretched polyethylene terephthalate fiber (bonding fiber, fiber diameter: 22.6 μm, fiber length: 38 mm, cross section: circular) 80 mass%, and stretched polyethylene terephthalate fiber (second heat resistant fiber, Softening temperature: 240 ° C, fiber diameter: 8.8 µm, fiber length: 38 m
m, cross section: circular) 20 mass%, and opened by a carding machine to form a unidirectional fiber web A (area density: 30 g / m ² ) in which fibers are oriented in the length direction of the fiber web. . On the other hand, meta-type aromatic polyamide fiber (first heat-resistant fiber, carbonization temperature: 500 ° C., fiber diameter: 12.4 μm,
Fiber length: 38 mm, cross section: circular) 60 mass%, undrawn polyethylene terephthalate fiber (bonding fiber, fiber diameter: 22.6 μm, fiber length: 38 mm, cross section: circular) 4
0 mass%, and opened by a carding machine to form a unidirectional fiber web B (area density: 30 g / m ² ) in which fibers are oriented in the length direction of the fiber web. Next, in a state where the unidirectional fiber web A and the unidirectional fiber web B are laminated, the unidirectional fiber web A and the unidirectional fiber web B are passed between a steel roll and a cotton roll set at a temperature of 210 ° C. (linear pressure: 490 N / cm). Then, the whole surface was bonded with polyethylene terephthalate derived from undrawn polyethylene terephthalate fiber to produce a nonwoven fabric having an areal density of 60 g / m ² , a thickness of 100 μm, and an apparent density of 0.6 g / cm ³ , that is, an oil removal sheet. Observation of an electron micrograph of a cross section of the oil removal sheet revealed that polyethylene terephthalate (binding resin) present in the region A was mostly in the thickness direction of the fiber sheet rather than in the thickness direction of the fiber sheet. It was in a flat state in which the lengths in the orthogonal direction were longer and combined. The average area ratio (N = 10) in the region A was measured from an electron micrograph of the cross section of the oil removal sheet, and was about 18%. The fibers present in the region A are only drawn polyethylene terephthalate fibers (second heat resistant fibers),
The average fiber diameter was 8.8 μm. On the other hand, when the average area ratio (N = 10) in the region B was measured from an electron micrograph of the cross section of the oil removal sheet, it was found to be
3%. The fibers present in the region B were only meta-type aromatic polyamide fibers (first heat-resistant fibers), and the average fiber diameter was 12.4 μm. The average surface roughness (N = 10) on one surface (A) of this oil removal sheet was 2.5 μm, and the average surface roughness (N = 10) on the other surface (B) was 3.7 μm.
Met.

(Example 2) Undrawn polyethylene terephthalate
Fiber (bonding fiber, fiber diameter: 22.6 μm, fiber length:
38mm, cross section: circular) 95% by mass
Tylene terephthalate fiber (second heat resistant fiber, softening temperature
Degree: 240 ° C, fiber diameter: 8.8 µm, fiber length: 38 m
m, cross section: circular) 5 mass% with a card machine
And the fibers are oriented unidirectionally in the length direction of the fiber web
Fiber web A (Area density: 30 g / m ^Two) Formed
Except that the surface density was 60 g /
m^Two, Thickness 100μm, apparent density 0.6g / cm^ThreeNon-woven
A fabric, an oil removal sheet, was manufactured. This oil remover
Observing the electron micrograph of the cross section of the sheet
And polyethylene terephthalate present in region A
Resin (bonding resin) is mostly in the thickness direction of the fiber sheet
Direction perpendicular to the thickness direction of the fiber sheet rather than the length
In a flat state where the length at
Was. Also, electron microscopy in the cross section of the oil removal sheet
From the mirror photograph, the average area ratio (N = 10) in region A
The measured value was about 6%. In addition, it exists in the A area.
The fibers are drawn polyethylene terephthalate fibers
(Second heat-resistant fiber) only, and the average fiber diameter is 8.
It was 8 μm. On the other hand, in the cross section of the oil removal sheet,
The average area ratio (N
= 10) was about 58%. In addition,
The fibers present in region B are meta-type aromatic polyamide fibers
Only fiber (first heat resistant fiber), the average fiber diameter of which is 1
It was 2.4 μm. Also, one of the oil removal sheets
The average surface roughness (N = 10) on one surface (A) is
1.9 μm, average surface on the other surface (B)
The roughness (N = 10) was 3.3 μm.

(Comparative Example 1) Undrawn polyethylene terephthalate fiber (bonding fiber, fiber diameter: 22.6 μm, fiber length:
38 mm, cross section: circular, 70 mass%, drawn polyethylene terephthalate fiber (second heat resistant fiber, softening temperature: 240 ° C., fiber diameter: 8.8 μm, fiber length: 38 m)
m, cross section: circular) of 30 mass% and opened by a carding machine to form a unidirectional fiber web A (area density: 30 g / m ² ) in which the fibers are oriented in the length direction of the fiber web. Except for this, the surface density is 6
0 g / m ² , thickness 100 μm, apparent density 0.6 g / cm ³
, That is, an oil removal sheet. Observation of an electron micrograph of a cross section of the oil-removed sheet revealed that the polyethylene terephthalate resin (binding resin) present in the region A was mostly in the thickness direction of the fiber sheet rather than in the thickness direction of the fiber sheet. In the direction orthogonal to the plane was longer. From the electron micrograph of the cross section of the oil removal sheet, the average area ratio in the region A (N = 1)
0) was about 29%. The fibers present in the region A were only drawn polyethylene terephthalate fibers (second heat-resistant fibers), and the average fiber diameter was 8.8 μm. On the other hand, when the average area ratio (N = 10) in the region B was measured from an electron micrograph of the cross section of the oil removal sheet, it was about 61%.
The fibers present in the region B were only meta-type aromatic polyamide fibers (first heat-resistant fibers), and the average fiber diameter was 12.4 μm. Further, the average surface roughness (N = 1) on one surface (A) of the oil removal sheet.
0) was 3.1 μm, and the average surface roughness (N = 10) on the other surface (B) was 4 μm.

(Comparative Example 2) Undrawn polyethylene terephthalate fiber (binding fiber, fiber diameter: 22.6 μm, fiber length:
38 mm, cross section: circular, 40 mass%, and meta-type aromatic polyamide fiber (first heat resistant fiber, carbonization temperature: 500)
° C, fiber diameter: 12.4 µm, fiber length: 38 mm, cross section:
60 mass%, and opened by a carding machine to form a unidirectional fiber web (area density: 60 g / m ² ) in which fibers are oriented in the length direction of the fiber web. Next, only the unidirectional fiber web is passed between a steel roll and a cotton roll set at a temperature of 210 ° C. (linear pressure: 490 N / cm), and is entirely derived from undrawn polyethylene terephthalate fibers. Bonded by polyethylene terephthalate to obtain an areal density of 60 g / m ² ,
A nonwoven fabric having a thickness of 100 μm and an apparent density of 0.6 g / cm ³ ,
That is, an oil removal sheet was manufactured. From the electron micrograph of the cross section of the oil removal sheet, the average area ratio (N = 10) in the region from one surface to 20 μm in the thickness direction of the fiber sheet, and 20 μm from the other surface in the thickness direction of the fiber sheet When the average area ratio (N = 10) in the regions up to the above was measured, each region was about 60%. The average surface roughness (N = 10) on one surface of the oil removal sheet and the average surface roughness (N = 10) on the other surface were both 4 μm.

(Comparative Example 3) Undrawn polyethylene terephthalate fiber (binding fiber, fiber diameter: 22.6 μm, fiber length:
38 mass%, cross section: circular, 80 mass%, meta-type aromatic polyamide fiber (first heat resistant fiber, carbonization temperature: 500)
° C, fiber diameter: 12.4 µm, fiber length: 38 mm, cross section:
And 20% by mass (circular), and opened by a carding machine to form a unidirectional fiber web (area density: 30 g / m ² ) in which fibers are oriented in the length direction of the fiber web. Next, only the unidirectional fiber web is passed between a steel roll and a cotton roll set at a temperature of 210 ° C. (linear pressure: 490 N / cm), and is entirely derived from undrawn polyethylene terephthalate fibers. Combined with polyethylene terephthalate to obtain an areal density of 30 g / m ² ,
A nonwoven fabric having a thickness of 50 μm and an apparent density of 0.6 g / cm ³ , that is, an oil removal sheet was produced. From the electron micrograph of the cross section of the oil removal sheet, the average area ratio (N = 10) in the region from one surface to 20 μm in the thickness direction of the fiber sheet, and 20 μm from the other surface in the thickness direction of the fiber sheet When the average area ratio (N = 10) in the regions up to was measured, all the regions were approximately 2%.
It was 0%. The average surface roughness (N = 10) on one surface and the average surface roughness (N = 10) on the other surface of this oil removal sheet were both 2.8 μm.

(Evaluation of Oil Removal Sheet) (1) Evaluation of Oil Removal Property: Fixing Roll whose Surface is Made of RTV Silicone Rubber (1 mm Thickness) and RTV whose Surface is
A color copying machine comprising a pressure roller made of silicone rubber (thickness: 2 mm) and having a fixing device having a built-in heater in each roll was prepared. Then, Example 1
To move the oil removal sheets of Comparative Examples 1 to 3 in the direction opposite to the rotation direction of the fixing roll, respectively.
In addition, the oil removal sheet is supplied such that the surface (A) thereof is in contact with the fixing roll (the oil removal sheets of Comparative Examples 2 and 3 are supplied such that one of the surfaces is in contact with the fixing roll).
Then, it was set so that the supplied oil removal sheet could be pressed against the fixing roll (nip width: 3 mm, pressing force: 0.05 kg / cm) by a cylindrical pressing roller made of foamed silicone rubber. And copy the photo image with OHP
Ten sheets were continuously performed on the film (copy sheet). Next, the tenth OHP film was projected by a projector, and oil streaks on the OHP film were visually observed. The results were as shown in Table 1. (2) Evaluation of oil retention: Using the color copying machine (with an oil removal sheet installed) used in the evaluation of the oil removal property, OHP in a state where the oil removal sheet is not moved (fixed state). 100 copies of the film (copy sheet) were made. Next, the 100th OHP
Oil streaks on the film were visually observed. The results were as shown in Table 1.

【table 1】 #: ◎ ・ ・ No oil streaks are observed ○ ・ ・ No oil streaks are observed but slight oil unevenness is observed △ ・ ・ Thin oil streaks can be observed × ・ ・ Oil streaks can be clearly observed

From the results of Example 1 and Comparative Example 1, when the average area ratio in the region A is 25% or less, or when the average surface roughness on the surface (A) is 3 μm or less, the oil removing property and the oil retaining property are obtained. Was found to be excellent. Also,
From the results of Example 1 and Comparative Example 3, if the average area ratio in the region B exceeds 25%, or if the average surface roughness in the surface (B) exceeds 3 μm, the oil removal property and the oil retention It turned out that it was excellent.

[0028]

The surface (A) of the fiber sheet contained in the area A of the oil-removed sheet for oil deposits of the present invention is very smooth, so that the surface (A) can be brought into contact with the oil deposits. In this case, the oil on the surface of the oil deposit can be uniformly wiped and removed. Further, since the region B has a coarser structure than the region A, a large amount of oil removed by the region B can be retained. If the average fiber diameter of the fibers present in the region A is 11 μm or less, the fiber sheet surface (A) contained in the region A
Is even smoother, so that if the surface (A) is brought into contact with oil deposits, the oil on the surface of the oil deposits can be more evenly wiped off and removed.

Since the surface (A) of another oil removing sheet of the present invention is very smooth, if this surface (A) is brought into contact with oil deposits, the oil on the surface of the oil deposits is evenly wiped off. , Can be removed. Further, since the fiber sheet surface (B) has a rougher structure than the fiber sheet surface (A), a large amount of oil removed near the fiber sheet surface (B) can be retained.

[0030] Since the oil removing material for oil deposits of the present invention can always bring a new surface of the oil removal sheet into contact with the oil deposit surface, the oil on the oil deposit surface can be uniformly wiped and removed. At the same time, a large amount of removed oil can be retained.

[0031] The oil removing device for oily deposits of the present invention can always bring a new surface of the oil removal sheet into contact with the surface of the oily deposits, so that the oil on the surface of the oily deposits can be uniformly wiped and removed. At the same time, a large amount of removed oil can be retained.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a fixing unit.

2A is an enlarged schematic cross-sectional view showing the thickness of oil on the surface of a fixing roll after wiping with a conventional cleaning sheet. FIG. 2B is a fixing roll after applying oil with a conventional oil coating device. Typical enlarged sectional view showing the thickness of oil on the surface

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixing roll 2 Pressure roll 3 Copy sheet 3a Unfixed toner 4 Oil coating device 4a Oil 5 Cleaning sheet

Claims (5)

[Claims] 1. A fiber sheet including a heat-resistant fiber that does not melt even when it comes into contact with an oil deposit from which oil is to be removed, and a binding resin that bonds the heat-resistant fibers to each other, and a cross section of the fiber sheet. In the above, the binder resin present in a region (region A) from one surface (A) to the thickness direction of the fiber sheet up to 20 μm is mainly in the thickness direction of the fiber sheet rather than in the thickness direction of the fiber sheet. The fiber sheet component existing in the region A is bonded in a state where the length in the direction orthogonal to the direction A is longer, and the fiber sheet component material other than the bonding resin existing in the region A occupies. The average area ratio to the whole is 25% or less,
And the other surface (B) in the cross section of the fiber sheet.
The average area ratio occupied by the fiber sheet components other than the binder resin existing in the region (region B) up to 20 μm in the thickness direction of the fiber sheet with respect to the entire fiber sheet components existing in the region B is An oil removal sheet for oil deposits, characterized in that it exceeds 25%. 2. The fiber according to claim 1, wherein an average fiber diameter of the fibers present in the region A is 11 μm or less.
The oil removal sheet for oil deposits according to the above. 3. A fiber sheet including a heat-resistant fiber that does not melt even when it comes into contact with an oil deposit from which oil is to be removed, and a binding resin that bonds the heat-resistant fibers to each other. Has an average surface roughness (Ra) of 3 μm or less on the surface (A), and has an average surface roughness (Rb) of 3 μm on the other surface (B) of the fiber sheet.
An oil removal sheet for oily deposits, characterized in that 4. An oil removing sheet for oil deposits according to claim 1, wherein one end of the oil removing sheet for oil deposits is wound around a shaft, and the other end of the oil removal sheet for oil deposits is different from the other. An oil removing material for oil deposits, which is fixed to a shaft. 5. An oil removal sheet for oil deposits is unwound from the oil removal material for oil deposits according to claim 4, and the unwound oil removal sheet for oil deposits is pressed against the oil deposits by pressing means. An oil removing device for oil deposits, further comprising a mechanism for winding up the pressed oil removing sheet for oil deposits.